Abstract: The present invention relates to a method and an apparatus for diagnosing low voltage of a secondary battery cell. The method for diagnosing low voltage of a secondary battery cell according to an embodiment of the present invention includes pre-aging a battery cell, charging the battery cell according to a preset charging condition, measuring a parameter for determining low voltage failure of the battery cell, comparing the measured parameter with a reference parameter, and performing formation when the battery cell is determined to be normal.

Abstract: The present disclosure relates to a secondary battery. The secondary battery may include an electrode assembly including a plurality of positive electrode plates with each plate having a positive electrode tab, a plurality of negative electrode plates with each plate having a negative electrode tab, and a plurality of separators with each separator interposed between a positive electrode plate and a negative electrode plate, a case accommodating the electrode assembly, and a tab welding portion comprising welded overlapping positive electrode tabs and welded overlapping negative electrode tabs. A length of the tab welding portion in an extension direction of the positive electrode tab or the negative electrode tab may be constant or different across a thickness direction of the positive electrode tab or the negative electrode tab.

Abstract: A secondary battery comprises an electrode assembly, a can, and an insulator. The electrode assembly includes a first electrode, a separator, and a second electrode alternately stacked and wound. The can has an accommodation part accommodating the electrode assembly therein, and the can comprises a first can and a second can having cylindrical shapes open in a direction facing each other. The insulator insulates an overlapping portion between the first can and the second can. The first can is electrically connected to the first electrode, and the second can is electrically connected to the second electrode. The insulator has a short-circuit induction through-part defined by a through-hole or a cutoff line, such that a short circuit occurs between the first can and the second can through the short-circuit induction through-part when it is deformed in shape as heat or a pressure is applied to contract or expand the insulator.

Abstract: Disclosed is a circuit for preventing an output of a pop noise, which occurs from an audio amplifier when a power switch of an electronic device loading the amplifier is turned on/off. The circuit may comprises an analog switch for switching an electrical connection between an audio amplifier and a speaker, and a signal delay circuit capable of respectively delaying times that the operating states of the analog switch and the power supply are changed when the power switch is turned on/off, and it is structured such that the analog switch is already opened state at the time that the power supply is on/off. Accordingly, it is possible to prevent the pop noise from being outputted through a speaker connected to the amplifier. The circuit of the invention can be applied to a variety of electronic devices having an audio amplifier.